From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8B702D47E6; Mon, 30 Mar 2026 14:32:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774881179; cv=none; b=YOgzKLUQydACrAaYCI+koqgeSmMm3u5qddgW7LyfeigJKHkoWSzPiiPNilB8b9OLyhO2y4HbRvc41uiKrYxtK8eBKRjcrOjy8xxNy1v1P09mwhIhAv4jA3tkHmDHdmCcb9ZegmE5XxdotQ9ZutmHgGA46WkVxygxN9/JupF08hQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774881179; c=relaxed/simple; bh=xjr7kjou/tlAs0NhQalT16hEuisWbUPGKwa8r2BLoUM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RFjtaRPAEtjeNttFh0NPKWnAlsJ+hjm6a9rpWgsCGGKTxGHnjb/pjHVWrnjLHQLp85KfemAUgCk1xbzAUSCZf2NEluHgc3dPU3Gct/nkDy81tL+vItEGasmGYYDNbqHwUPX/o1xTFUtycV26/zlcVXMa4No6QbYBksrRrT76PHQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cFMOA622; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cFMOA622" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3F48C19423; Mon, 30 Mar 2026 14:32:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774881179; bh=xjr7kjou/tlAs0NhQalT16hEuisWbUPGKwa8r2BLoUM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cFMOA622GQDBbIbb7ykclQ78rkJ9Ui7Gd5cavChoATHqusu9WCtXerl+YgM1ePZ5L 8K5CFq/Ovav042bPqAY/Y7UsFTMQWfPwQu0JZ5uiF+ln+QcVa72a1irZjXlgt17m9/ a7BhqN0tlYSyw9RzED3n6zaPfYUk9gU2KsZZfKnuKDOqkfmpGN4VpKE9KmsJvHBKz4 mrYcu5DG/3JvZH5PFLp4Xx/PjIdd7yf+TK192FygAXxXILhqxaolyEI/PpIJ3s8pQK mfimSHvzxhIxRKQPYyWtn7HFn4O33Y+hTFHPi8sDu8b254uuNZVOeGs81bJ7+dW5Sb up7fbuzzkOK+w== Message-ID: Date: Mon, 30 Mar 2026 15:32:55 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 2/3] media: qcom: camss: Add CAMSS Offline Processing Engine driver To: johannes.goede@oss.qualcomm.com, Dmitry Baryshkov Cc: Loic Poulain , vladimir.zapolskiy@linaro.org, laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com, robh@kernel.org, krzk+dt@kernel.org, andersson@kernel.org, konradybcio@kernel.org, linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, mchehab@kernel.org References: <20260323125824.211615-1-loic.poulain@oss.qualcomm.com> <20260323125824.211615-3-loic.poulain@oss.qualcomm.com> <1ba54ec0-be51-4694-a79b-f272e76303d2@kernel.org> <12194cc0-0960-486c-be7e-1a22d95de340@kernel.org> <7fc31426-3157-49c7-a30d-dcd7b181fcc6@oss.qualcomm.com> <8DTHyPLaUjGKd83PvBsisjn_SnpUnvkateTtwz9P6CChP9VGfDyQmJa4Rfd5KwOBOLhtGFJPDzfHrXC4zvV-Fg==@protonmail.internalid> <0330f63f-7137-4484-954a-fc0776a9b052@oss.qualcomm.com> <0879e4c1-5381-4a70-9fb3-4af9b3bf6e48@kernel.org> <0RTUgDf1wbD0phPk8qAcojZovgMA_68R84FRaL_BHfjzupSA6c_8S5ogVerViYPFNJtvup9sOvL_uPx2t6-KCg==@protonmail.internalid> <2e4c4641-f631-48fa-b5dd-6efd70110dd6@oss.qualcomm.com> From: Bryan O'Donoghue Content-Language: en-US In-Reply-To: <2e4c4641-f631-48fa-b5dd-6efd70110dd6@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 30/03/2026 15:27, johannes.goede@oss.qualcomm.com wrote: >> That's another reason I bring up CDM again and again. We probably don't want to fix to the wrong format for OPE, introduce the CDM and then find we have to map from one format to another for large and complex data over and over again for each frame or every N frames. > CDM is a much lower-level API then what is expected from > a media-controller centric V4L2 driver. Basically the OPE > driver will export: My concern is about wrappering one thing inside of another thing and then stuffing it again back into CDM and doing the same on the way out. There are already 50 MMIO writes in the OPE ISR, I don't believe it is sustainable to keep adding MMIO into that. I'm aware of a project in qcom that did something with making the CDM format in libcamera and handed that off to kernel, recommend looking into that. --- bod